Visnja Ivancan

Pretransplant and perioperative predictors of early heart transplantation outcomes

Aim To identify predictors of 3-month mortality after heart transplantation in a Croatian academic center. Methods A retrospective review of institutional database identified 117 heart transplantations from January 2008 to July 2014. Two children <14 years were excluded from the study. The remaining 115 patients were dichotomized into survivors and non-survivors adjudicated at 3-months postoperatively, and their demographic, clinical, and longitudinal hemodynamic data were analyzed. Results 3-month survival after heart transplantation was 86%. Non-survivors were older (59 ± 8 vs 50 ± 14 years, P = 0.009), more likely to have previous cardiac surgery (44% vs 19%; odds ratio [OR] 3.28, 95% confidence interval [CI] 1.08-9.90; P = 0.029), lower body mass index (BMI) (25 ± 4 vs 28 ± 2 kg/m2, P = 0.001), and be diabetics (44% vs 23%; OR 2.57, 95% CI 0.86-7.66; P = 0.083). Creatinine clearance was marginally superior among survivors (59 ± 19 vs 48 ± 20 mL/min, P = 0.059). Donor age and sex did not affect outcomes. Non-survivors were more likely to have had ischemic cardiomyopathy (69% vs 32%, P = 0.010). Postoperative utilization of epinephrine as a second line inotropic agent was a strong predictor of mortality (63% vs 7%; OR 21.91; 95% CI 6.15-78.06; P < 0.001). Serum lactate concentrations were consistently higher among non-survivors, with the difference being most pronounced 2 hours after cardiopulmonary bypass (9.8 ± 3.5 vs 5.2 ± 3.2 mmol/L, P < 0.001). The donor hearts exhibited inferior early hemodynamics in non-survivors (cardiac index 3.0 ± 1.0 vs 4.0 ± 1.1 L/min/m2, P = 0.001), stroke volume (49 ± 24 vs 59 ± 19 mL, P = 0.063), and left and right ventricular stroke work indices (18 ± 8 vs 30 ± 11 g/beat/m2, P < 0.001 and 5 ± 3 vs 7 ± 4 g/beat/m2, P = 0.060, respectively). Non-survivors were more likely to require postoperative re-sternotomy (50% vs 12%; OR 7.25, 95% CI 2.29-22.92; P < 0.001), renal replacement therapy (RRT) (69% vs 9%; OR 22.00, 95% CI 6.24-77.54; P < 0.001), and mechanical circulatory assistance (MCS) (44% vs 5%; OR 14.62, 95% CI 3.84-55.62; P < 0.001). Binary logistic regression revealed recipient age (P = 0.024), serum lactates 2 hours after CPB (P = 0.007), and epinephrine use on postoperative day 1 (P = 0.007) to be independently associated with 3-month mortality. Conclusion Pretransplant predictors of adverse outcome after heart transplantation were recipient age, lower BMI, ischemic cardiomyopathy, reoperation and diabetes. Postoperative predictors of mortality were inferior donor heart hemodynamics, epinephrine use, and serum lactate concentrations. Non-survivors were more likely to require re-sternotomy, MCS, and RRT.

Results of extracorporeal life support implementation in routine clinical practice: single center experience

Aim To describe our experience in the clinical application of extracorporeal life support (ECLS) and analyze whether ECLS leads to acceptable clinical outcomes in patients with cardiac failure. Methods Data from clinical database of University Hospital Center Zagreb, Croatia, on 75 patients undergoing ECLS support from 2009 to 2014 due to cardiac failure were retrospectively analyzed. Outcomes were defined as procedural and clinical outcomes. ECLS as a primary procedure and ECLS as a postcardiotomy procedure due to inability to wean from cardiopulmonary bypass were analyzed. Results ECLS was used in 75 adult patients, and in 24 (32%) of those procedural success was noted. ECLS was implemented as a primary procedure in 36 patients and as a postcardiotomy procedure in 39 patients. Nine out of 39 (23.08%) patients had postcardiotomy ECLS after heart transplantation. Bleeding complications occurred in 30 (40%) patients, both in primary (11/36 patients) and postcardiotomy group (19/39 patients). ECLS was established by peripheral approach in 46 patients and by central cannulation in 27 patients. In 2 patients, combined cannulation was performed, with an inflow cannula placed into the right atrium and an outflow cannula placed into the femoral artery. Eleven patients treated with peripheral approach had ischemic complications. Conclusion ECLS is a useful tool in the treatment of patients with refractory cardiac failure and its results are encouraging in patients who otherwise have an unfavorable prognosis.

Diagnostic accuracy of central venous saturation in estimating mixed venous saturation is proportional to cardiac performance among cardiac surgical patients

PURPOSE Advanced hemodynamic monitoring in cardiac surgery translates into improvement in outcomes. We evaluated the relationship between central venous (ScvO2) and mixed venous (SvO2) saturations over the early postoperative period. The adequacy of their interchangeability was tested in patients with varying degrees of cardiac performance. METHODS In this prospective observational study, we evaluated 156 consecutive cardiac surgical patients in an academic center. The ScvO2 and SvO2 data were harvested from 468 paired samples taken preoperatively (T0), after weaning from cardiopulmonary bypass (T1) and on postoperative day 1 (T2). RESULTS The relationship between ScvO2 and SvO2 was inconsistent, with inferior correlations in patients with lower cardiac indices (CI) (Pearson r(2) = 0.37 if CI ≤2.0 L/min per square meter vs r(2) = 0.73 if CI >2.0 L/min per square meter, both P < .01). Patients with lower CI also had wider 95% limits of agreement between SvO2 and ScvO2. The proportion of patients with a negative SvO2-ScvO2 gradient increased over time (48/156 [31%] at T0 to 73/156 [47%] at T2; P < .01). This subgroup more frequently required inotropes at T2 than patients with a positive SvO2-ScvO2 gradient (odds ratio, 6.46 [95% confidence interval, 0.81-51.87], P = .06) and also had higher serum lactate levels (1.5 ± 0.8 vs 1.0 ± 0.4; P < .01). CONCLUSIONS The diagnostic accuracy of ScvO2 for estimating SvO2 is proportional to cardiac performance. A negative SvO2-ScvO2 gradient at T2 correlated with inotropic support requirement, higher operative risk score, age, lactate level, and duration of cardiopulmonary bypass.

Impact of aspirin resistance on antiplatelet therapy management after coronary artery surgery

Dual antiplatelet therapy (APT) provides incremental platelet inhibition compared with either agent alone and more effective suppression of adverse ischaemic events [2]. This finding is confirmed by Awidi and coworkers who found that the combination of aspirin and clopidogrel had greater inhibitory effects on platelet aggregation than either agent alone in patients with coronary artery disease [3]. In our opinion, the addition of clopidogrel in the group of patients with AR inevitably affected both the observed clinical outcomes and the decrease in AR proportion. Following CAS, extensive evidence supports the use of aspirin, in doses of 100–325 mg/day, to be administered postoperatively and continued indefinitely [4]. A daily 100 mg dose of aspirin administered postoperatively in a study by Wang et al. [1], allows the possibility of different APT management strategies. For example, a stepwise increase in the aspirin dose with a subsequent platelet function assessment could probably bring a further decrease in the AR proportion and therefore, eliminate the need for dual APT. However, it still remains unclear, whether an aspirin dose increase would be superior to dual APT, in the context of a clinical outcome. Of note, a meta-analysis by Snoep et al. showed an overall prevalence of 21% of laboratory-defined clopidogrel low response [5]. We believe that these two different APT approaches should be evaluated in a large cohort randomized trial with an outcome evaluation of both ischaemic and bleeding events. The authors hypothesized that the Chinese population is more sensitive to aspirin therapy and presented no AR at a 6-month follow-up. It would be interesting if the authors analyzed the bleeding event occurrence at the 6-month follow-up in the group of patients on dual APT. APT management in cases of AR should be individually tailored, with aspirin dosage stepwise increased (up to 325 mg/day), and clopidogrel administration in cases of AR to high aspirin doses. Temporary AR requires temporary APT adjustment. The duration and intensity of the APT adjustment should be tailored according to drug specific platelet function tests in order to minimize both ischaemic and bleeding events. In conclusion, it is difficult to investigate by what amount the laboratory AR corresponds to the clinical AR. Prospective studies, with a large study sample necessitated by the infrequency of adverse ischaemic events, must determine the optimal threshold for AR, taking into consideration both the laboratory and clinical outcome findings.

Impact of Remote Ischemic Preconditioning Preceding Coronary Artery Bypass Grafting on Inducing Neuroprotection (RIPCAGE trial)

Background: Neurological complications after coronary artery bypass grafting (CABG) reduce quality of life, increase mortality, and inflate resource utilization. The risk of postoperative neurological complications parallels the increasing risk burden of the contemporary patient population. We evaluated the efficacy of remote ischemic preconditioning (RIPC) on inducing neuroprotection. Methods: Seventy patients undergoing first‐time CABG were randomly assigned to RIPC or a sham procedure. Structural brain magnetic resonance imaging (MRI) was complemented with functional connectivity MRI to gain a whole‐brain global connectivity analysis. Paired neurocognitive and MRI data were acquired pre‐ and postoperatively. The primary end point was a composite of new ischemic brain lesions and neurocognitive impairment. Secondary end points included brain connectivity profiles, pooled ischemic volumes, and individual components of the primary outcome. The Shapiro–Wilk test was used to determine whether a data set followed a normal distribution. The Fisher exact test was used to calculate the measures of association for categorical variables, whereas continuous data were tested with either the Mann–Whitney U test or the Student t test. Results: There was no between‐group difference in the incidence of the primary end point (9 [27%] in the RIPC group vs 8 [24%] in the control group, odds ratio, 1.17 [95% confidence interval, 0.34‐4.06]; P = 1.0). Although RIPC did not reduce the incidence of brain ischemia (8/33 [24%] vs 7/33 [21%]; P = 1.0), the pooled ischemic volume was lower in the RIPC group (157 [interquartile range, 125‐231] vs 777 [interquartile range, 564‐965] mm3; P = .004). Postoperative neurocognition was marginally superior in the RIPC group as evidenced by a lower absolute number of abnormal neurocognitive tests in the RIPC group (7/99 [7%] vs 16/99 [16%]; odds ratio, 0.40 [95% confidence interval, 0.14‐1.09]; P = .074). Robust reductions of functional connectivity profiles for the associative thalamus were documented in both groups, irrespective of RIPC (RIPC group, t = 3.31; P < .01; and the control group, t = 3.52; P < .01). Conclusions: Silent brain ischemia occurs frequently after CABG. RIPC did not reduce the incidence of the primary outcome. However, RIPC significantly reduced the pooled volume of ischemic brain lesions. Surgery adversely affected global brain connectivity, with RIPC conferring no demonstrable protection. The association of RIPC with superior neurocognitive test scores failed to cross the threshold for significance. Graphical abstract Figure. No Caption available.

The change in pulmonary vascular resistance after left ventricular assist device implantation - the predictive role of platelets revisited

E-mail: marijan.pasalic@yahoo.com Purpose: While analyzing the group of patients implanted with a left ventricular assist device (LVAD) at our institution to verify which of the preand postoperative factors constitute the optimal survival outcome predictors, we determined a significant increase in postoperative pulmonary vascular resistance (PVR) values in the expired patients1. The aim of this study was to further analyze the data in order to determine which of the preoperative factors were related to the aforementioned increase in postoperative PVR values. Methods: For the 20 patients (18 M, 2 F; mean age 58.7±8.3 years) that have been implanted with an LVAD in our institution during the past 2 years, preimplantation echocardiography, right heart catheterization (RHC) and laboratory data were collected and compared according to the values of the postimplantation PVR. The groups were compared by using the adequate statistical test (t-test, Mann Whitney U test, statistical significance set at 0.05). Correlation analysis and linear regression were performed. Results: Among the 20 patients, 14 had postoperative RHC data and 4 of them were proven to have elevated PVR values (>2.4 WU). When comparing the pts. with elevated to those with normal PVR values, no significant difference was found neither in the RV function (FAC 33±7% vs 22±12%, TAPSE 1,0±0,7 cm vs 1.6±0.5 cm, NS), nor in the RV and LV dimensions (RVIDd 34±9 mm vs 35±12 mm, LVIDd 65±10 mm vs 73±9 mm). The borderline significance was found in the left ventricular EF (28±3% vs 19±8%, p=0.06) and the degree of the MR (median values 1 vs 2, p=0.05). The preoperative RHC parameters were not found to be predictive of changes in postoperative PVR (preoperative PVR 4,2±3,4 vs 3,4±1,5 WU, C.I. 1,8±0,7 vs 1,9±0,4 L/min/m, TPG 14±11 vs 13±4 mmHg and RVSWI 11,4±2,2 vs 8,9±2,1, NS). As for the laboratory values, only the platelet count significantly differed between the groups (128 ±73 vs 246±65 E3/mm, p<0.05). The correlation analysis showed a strong negative correlation between the platelet count and postoperative PVR values (r=-0,761, p<0.01). The linear regression verified the following relationship between the variables PVR=6,247-0,017xPLT, p<0.01). Conclusion: These preliminary data show that the platelet count is a significant predictor of the postoperative PVR values in patients with an LVAD (a previously shown survival predictor1). Further investigation will be conducted to explain the role of platelets in the etiology of PVR in our group of pts.

How To Manage Aspirin Resistance Early After Coronary Artery Bypass Grafting

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